Sync

Task/Anonymous-recursion/D/anonymous-recursion-1.d

@@ -1,9 +1,14 @@
-uint fib(in uint n) pure nothrow {
-    immutable self = &__traits(parent, {});
-    return (n < 2) ? n : self(n - 1) + self(n - 2);
+import std.stdio, std.exception;
+
+int fib(int arg) pure {
+    enforce(arg >= 0);
+
+    return function int (int n) pure nothrow {
+        auto self = __traits(parent, {});
+        return (n < 2) ? n : self(n - 1) + self(n - 2);
+    }(arg);
 }
 
 void main() {
-    import std.stdio;
-    writeln(fib(39));
+    39.fib.writeln;
 }